Thermostatic



July 16, 1929. R. l.. sKlNNER THERMOSTATIC APPLIANCE Filed May 26, 1928 1% v MZ?" '55 sirably valso under sub-atmospheric pressure,

speciie employment.l l

v One of the leading aims or purposes of Patented` July 1 6, 1929. UNITEDl STATES vPAraNT ori-Icav RALPH L'SKINNER, OF DETROIT, MICHIGAN, ASSIGNOR T0 SKINNER AUTOMOTIVE DEVICE C0., INC.,OF DETROIT, MICHIGAN, A CORPORATION OF CALIFORNIA..

THEaMosTArIe ArrLIANcE.-

Application led May 26, 1928. Seri@- No. 280,737.

My invention pertains to thermostats, for example, those used to control or govern the opening and closing of valves, although the new structure is in no way limited to any the invention is the provision ofv a thermostat .which will be highly sensitive to temperature changes, which will have substantial movement and unusual power for its size, and which will be relatively small and compact so that it may be'satisfactorily employed. in installations affording small space.

In an ordinary, duplex-metal thermostatic bar, the power thereof may be increased by using a bar of greater thickness Y Figure Bis an enlarged end view of the which is always full.

or one of shorter length, but such change decreases its sensitivity to temperature variations, and the thermostat of this appliance requires both power and great sensitiveness.

Actordingly, the power of the new thermostat is made great by employing a plurality of short, thin, bi-metal strips associated together in series relation to obtain the cumulative edect of the plurality, the short length of the strips aording compactness of structure` and power, the thinness insuring a high degree of sensitiveness, and" the series relation of the strips multiplying the motion as required.

To enable those acquainted with this art to fullyunderstand the invention, both from structural and functional standpoints, in

the accompanying drawing forming a partI of this specification, I have illustratedin detail, a present, preferred embodiment of the invention, and, for simplicity, like reference numerals have been employed forthe same parts throughout the several views. L

In this drawing:

Figure 1 is a vertical section through' an, appllance l incorporating the new thermostatic structure;

' Figure 2 isV an enlarged section Eon line 2-2 of Figure 1; and

thermostat.

limproved thermostatic structure has been shown iny association with, and controlling the action of, an oil rectier or distillator, such as is employed with an internal-combustion engine to reclaim-its contaminated lubricant under the action of heat and de The impure oil to be purified by the driv- -ing off of its Volatile or gasitiabl'e polluting `constituents by heat is fed under pressure through a conduit 10 in a casting 11 ofirregular shape into an inclined, hollow screw 12 by means'of a cross-hole 13 ofthe latter.,

communicating with its longitudinal, central passage or port 14, the wall margin around the lower end of which forms a valve-seat for a conical-valve 15 having an external, circular shoulder 1G against which one end of a coiled spring 17 encircling the stem or shank 18 of the valve bears, the opposite end of the spring pressing against an inner shoulder 19 of a hollow, adjustment screw 20 threadedy into a cavity 21 of the specified casting 11.

Screw 12 may be readily removed for cleaning or replacement purposes and toassure that such screw, or its substitute, will always occupy the same position, thus not disturbing the adjustment of the valve which cooperates with it, the reduced-diameter, un.-

threaded part of the screw is provided with of an appropriate tool or wrench applied in any one or more of its cross recesses 24,. 24, which are provided specifically for that purpose, the screw, when once correctly set, being locked in such relation by a set-screw 26 and a lead plug 2 7 between the two screws to prevent injury to the thread of screw 20.

Chamberv or compartment "21 is equipped with a drain-pipe 28 which allows the oil 1 liowing down through the open valve to be delivered into a heated vessel 29 within an outer shell or casing 31, the heated oil overflowing from such container or receptacle IValve-stem 18 extends down through the central opening'in screw 20 through which it .may slide during the valve vopening and closing movements, the downwardly-protruding portion of such stem extending through registering, center apertures in a pair of reversely-eurved, bi-metal, -thermostatic i eley ments 32 and 33, each composedof a pair otmember 32 and to `prevent the air from asunited, metal strips of substantially different co-eiicients of expansion,vsuch thermostatic members being constantl immersed in the oil in the continuously-lille oil-vessel and hence always subject to the temperature of such body of oil. l

Valve-stem 18 at its lower end has an enrgement or shoulder 34 below, and co-oper- `ating with, the thermostaticmember 33, and,

in this connection, it should be observed that after the valve has closed under the action of its spring, such operation being permitted by the contraction of the multiple thermostat,

the latter may contract still more, as shown in Figure 2, withoutinfluencing the valve and withoutdetrimental effect on the thermostat, such as Subject-ing it to additional strain which would have a tendency to give it a permanent set. A v

The spring is strong enough to `close the valve against the maximum substantiallyluctuating oil-pressure in the. conduit l0, and the thermostat, when it opens the valve by its expansion, does so in opposition to the closing tendency of the spring. u

' Stated differently, the thermostat opens the valve against the spring action, and the spring closes the valve when permitted to do so by the thermostat.

e In order to have the thermostat operate to best advantage, it should be substantially frictionless, -and, accordingly, the end sections of each duplex-metal bar are reversely curved or roundedl somewhat at 35, so that the *two elements have rocking bearingson one anv other at their ends eliminating practically all frictionat such points.

To hold the two thermostatic-elements' in properrelation to one another atall times, andl with a minimum of friction, the lower part'of casting 11 is formed as al yoke 36, the arms of ywhich. have extensions 37, 37 vabove the heat;-v responsive e1e1nents32, 33, with knife-edges parte 32, 33, t us preventing or about the axis o von which they are mounted, but, at the same ftime, permitting them to. move axially of.l s uch `stem with very small resistance owing 'to the knife-edge contact.

-Toassnre that such thermostatic-members will ynot become unduly canted'on the valvestem, the ends of the yoke arms are `also conj The vfriction -dueto such contact is,l of` .lso course, small in" amount, so that the entire stituted as knife-edges 39, 39, designed, if occasion requires, to contact with thefadjacent suming an undue angular re ation to the valve-stemin their lown plane.v

'mountingof the'double thermostat" may be said to; practically. or substantially fric-` tionless.

Y, as the temperature ofthe' i1 in the vessel l increases and transmits suchheat tothe imwith the upper edges of the their rotation the valve-stemmersed thermostat, thebi-metal or-duplex bar 32 arches more inwardly toward the* valve and the correlated bar 33 arches inthe opposite direction, the ends of the bars rocking on v one another at 35, 35 as may be required. y

After such combined or conjoint bending has taken up the play or looseness 'of the thermostat between the end of screw 20 andy the valve-stem head 34, further bending of the members, due to the increasedheat, will cause the valve to open against, or in opposition to, the valve-closing tendency of the spring.

After the duplex or multiple thermostatvv has contracted sufliciently upon decrease of oil temperature, it allows the spring to close only vone pair of thermostatic-members has been shown, it will be apparent that as many of such elements may be used as is required to meet the particular situation-s` Those acquainted with this art will readily ed tot modified within comparatively wide or radical limits 4without departure from the heart multiple understand that the invention, as defnedby the ap ended claims,- is not limited or restrictlie precise and exact details of structure shownvandV described, and that these may be and essence of the invention and without `the loss of any of its substantial benefits and ad- 1 vantages.:

vI claim: 1'. In a multiple thermost'ati'c appliance, the

combination cfa pair of reverse y-bowed bimetal thermostatic-members,having reverse'. ly-rounded end portions adapted -to bear on one another without substantial friction, each.

of .said members being composed of two'metal strips of different co-eicients ofe'xpansion-,an

abutment against which the middle portion of one of said members may bear, means actuated `by said members operative] associated with4 the middle portion of saidot er thermostaticmember, spring-means actin on said actuated means 1n op ositionleto, ut incapable of overpowering, t e joint expanding action of,4 .120

said members, anti-friction knife-edge means co-acting with said thermostatic-members to prevent them -from turning about an axis through their centers, and anti-friction knifeedge means to prevent. said thermostatic--A .i

own plane. 4.

2. In a multiple thermostatic appliance' the metal the ostatic-,members having reversely-round end portions adapted to bearon combina of a. pair ofreverselybowed bimembers from canting substantially in their.,l

\one another Without substantial friction, each of said members being composed of two metal strips of different c-o-eiici'ents of expansion, an abutment against which the middleJ -por- 5 tion of one of said members may bear, means vciated with the middle portion of `said other thermostatic-member, spring-means acting on one another without substantial- :nf-rietlion', each of said members being composed of'tv'vo metal 26 strips of diderent co-elicients of expansion, an abutment against lWhich the middle portion of one of said members may bear, means actuated by said members operatively assosaid actuated means 1n opposition to, but incapable of overpowering, the joint expanding action of said members, and anti-friction knife-edge means to prevent said thermotheir own plane.` p J- In Witness whereof I have hereunto set my hand.

' RALPH' L. sKiNN/ER.

3o static-members' from canting substantially in v- 

